What it is and when to use it
This calculator applies the standard coffee-to-water ratio method used by coffee professionals and enthusiasts to find exactly how many grams (and tablespoons) of ground coffee to use for any batch size, from a single mug to a full carafe. Instead of eyeballing scoops, it works from the actual weight of the water you are brewing with and a target strength ratio, so the result scales correctly whether you are brewing one cup or twelve.
Use it for drip coffee, pour-over, French press, or any brew method where you know your water volume and want a consistent, repeatable strength. Choosing a stronger or weaker ratio from the dropdown lets you dial in taste preference without having to redo the math by hand every time you change batch size.
Coffee (g) = Water (g) / Ratio, where Water (g) ≈ Water (ml) since water is about 1 g/ml
Worked example
For 4 cups of water (32 fl oz) at the recommended 1:17 ratio: Water in milliliters = 4 × 236.588 = 946.35 ml, which is treated as 946.35 grams of water. Coffee needed = 946.35 / 17 = 55.7 g. In tablespoons: 55.7 / 5.3 = 10.5 tbsp — matching the calculator's default output for 4 cups at 1:17.
Common mistakes and how to interpret the result
- Measuring coffee by volume (scoops) instead of weight. Ground coffee's density varies by grind size and roast, so a "scoop" can vary 20% or more in weight — a kitchen scale gives a far more consistent result than a scoop.
- Confusing the ratio direction. A ratio of 1:15 uses more coffee per unit of water than 1:18, since dividing by a smaller number yields a larger coffee mass — lower ratio numbers mean stronger coffee, not weaker.
- Forgetting brew method affects the ideal ratio. French press and cold brew are typically brewed stronger (1:12 to 1:15) than drip or pour-over (1:16 to 1:18); pick the ratio that matches your method and taste, not just the default.
- Not accounting for water absorbed by the grounds. The calculator gives the water going into the brewer, but ground coffee absorbs roughly 2x its weight in water, so the final cup in your mug will be somewhat less than the water amount entered.
Frequently Asked Questions
Why does a lower ratio number mean stronger coffee?
Why does the calculator convert cups to grams of water?
Is 5.3 grams per tablespoon accurate for all coffee?
Which ratio should I pick if I've never measured coffee this way before?
Common Tip Percentages
| Service | Typical Tip Range | Notes |
|---|---|---|
| Restaurant (sit-down) | 15–20% | 20%+ for exceptional service |
| Food delivery | 10–20% | Consider extra for long distances |
| Taxi / rideshare | 10–20% | More for assistance with luggage |
| Hotel housekeeping | $2–5/night | Leave daily, not just at checkout |
| Barber / hair salon | 15–20% | On pre-discount total |
| Pizza delivery | 10–15% or $3–5 minimum | Higher in bad weather |
General Household Budget Ratios (50/30/20 Rule)
| Category | % of Net Income | Examples |
|---|---|---|
| Needs | 50% | Rent, groceries, utilities, insurance |
| Wants | 30% | Dining out, entertainment, hobbies |
| Savings / Debt | 20% | Emergency fund, retirement, extra payments |
Common Measurement Conversions for Everyday Use
| Quantity | US / Imperial | Metric Equivalent |
|---|---|---|
| 1 cup | 8 fl oz | 237 mL |
| 1 pint | 16 fl oz | 473 mL |
| 1 quart | 32 fl oz | 946 mL |
| 1 gallon | 128 fl oz | 3.785 L |
| 1 lb | 16 oz | 453.6 g |
| 1 ft | 12 in | 30.48 cm |